* Update free-programming-books-fi.md
* Fixed a link to author's own page
Found the original link from author's own page so there's no need to link to ResearchGate.
* Newline fix
We had a variety of ways to denote Wikibooks. It seemed appropriate to add "wikibooks" as the "author" and remove "wikibook" from the title, since the books don't use "wikibook" in their titles.
